The present invention relates to a novel antimicrobial agent, i.e. an antibacterial and antifungal agent, containing 2',6'-dihydroxy-9-(2,5-dihydroxyphenyl)octylphenone as an effective ingredient thereof and also to a method for preventing growth or multiplication of microorganisms in foodstuffs, cosmetics, medicines and the like. The inventive antimicrobial agent is particularly effective as an antibacterial agent or as an antifungal agent when incorporated into various kinds of foodstuffs, especially, containing little or no fats or oils, such as fruit wines or ratafias, jams, catchups, processed fish pastes, soy sauces and the like as well as various kinds of cosmetics and medicines.
Many kinds of antimicrobial or antiseptic agents are hitherto known and used in order to prevent growth of putrefactive bacteria and fungi in the above named foodstuffs, cosmetics and medicines including Parabens (alkyl ethers of p-hydroxybenzoic acid, products of Washine Chemical Corp.), benzoic acid, sorbic acid and other kinds of synthetic organic compounds. It is, however, a recent trend that the use of an antimicrobial agent of natural origin is recommended from the standpoint of higher safety than with synthetic ones provided that it has a satisfactorily high antibacterial and antifungal effects even by use of a small amount thereof.
In relation to the increasing demand for the antimicrobial agents of natural origin as described above, there have been published numbers of papers dealing with the antimicrobial effect of various kinds of spices and herbs or, in particular, the essential oils extracted therefrom. The problem in the use of spices and herbs or essential oils thereof as an antimicrobial agent, in particular, in foodstuffs is that the taste and flavor of the foodstuff are detrimentally affected by the too strong spiciness thereof since they must be added in an amount much larger than used in ordinary cooking in order to obtain sufficient antimicrobial effect.
Such an undesirable influence is similarly unavoidable in the use of spices and herbs in cosmetic materials and medicines because the very delicate balance of perfumes in cosmetics is fatally destroyed by the addition so large amounts of them and medicines are imparted with a strange smell which may adversely affect the patient psychologically.